Best dB/whp ratio for catback/turboback ?

Hey i am what you might call a "suit" (basically I wear a suit everyday for meeting w/ clients) no comments on that please, but would like a exhaust system that would give me the most gain while being relitivly quiet close to stock noise or a little louder. I know that all exhaust upgrades are going to produce higher SPL but any ideas on:

 

1) what to stay away from

2) recondmendations too suit (no pun intended) my needs

 

**I also know that there are many catbacks that allow you to

add silencers and remove them very easily however i would like to stay

away from them

Borla.

Looks good and sounds good. Not too loud.

^But what about power? That was 50% of his concern...

Fujitsubo.

If anything my car is almost too quiet!

megan racing single tip. very nice and almost too quiet.

My HKS silent hi power could be an option for you, the only thing i would be concerned about is the look, They are very aggressive looking which may be more conspicuos than the sound they produce which is deffenitley queit however I have a feeling that any noticible exuast tone that comes from aftermarket systems will be aggresive regardless of the noise, which is offensive however not as much as the high noise level that some of them produce. Today is my first day with it on so i want to tell you to get it. GET THE HKS SILENT HI POWER.

greddy evo2 full 3" catback(as most are). i have it, passes the girlfriend friendly test and like the fujitsubo almost too quiet. plus its less expensive then the fuji or hks. just my two cents

MR quad tip is pretty quiet in the car, but my car has EL headers

megan racing single tip. very nice and almost too quiet.

 

+1 since you can change silencers to suit the noise level you'd like. If you are going to stay under ~320whp, you can also use a 3" DP+mid+2.5"Y+stock cans and it is very close to stock noise levels but with only a slight power loss vs. 2.5" mufflers.

Out of curiosity, what's the point of doing a 3" DP with a 2.5" Y?

i thought i heard that greddy evo2 is loud?

I used to run the evo 2's i think its pretty loud, but thats just what i think.

 

There are a number of routes you could go. The megan's are pretty quiet, even without the silencers and can be acquired for a good price. Personally, if I were to do it all over again I would get the perrin mid and y pipes with prodrive mufflers. Perrin's over cobbs because the perrins have a resonator on them.

Out of curiosity, what's the point of doing a 3" DP with a 2.5" Y?

 

3" DP = 7.1 sq in cross section

2 x 2.5" Y-pipe = 2 x 4.9 sq in = 9.8 sq in cross section

 

A 2" Y-pipe (6.3 sq in) would be a bit smaller than the 3" DP. Is that what you were wondering?

3" DP = 7.1 sq in cross section

2 x 2.5" Y-pipe = 2 x 4.9 sq in = 9.8 sq in cross section

 

A 2" Y-pipe (6.3 sq in) would be a bit smaller than the 3" DP. Is that what you were wondering?

 

Well I got that, but when dealing with flow you deal with bottlenecks, and the point at which the 3" tapers to 2.5" in terms of restriction of flow, rather than capacity/total volume, would seem inhibiting.

 

Volume will certainly apply to the creation of backpressure in a good way, and it would definitely apply in the intake for reasons of pressurization/lag in that sense. But as far as diameter/restriction of flow I would think only the smallest diameter portion would matter. In this case the part of the Y before the split -- after the split, there would certainly be no problem.

what about the xcceleration TBE?

 

has anyone here have a electronic cutout like it?

 

heres a link http://www.xcceleration.com/itemdetails.cfm83.htm#leggtexhaust

FWIW, I have the stock exhaust and a catless UP and DP...it is hardly much difference. I don't think you're going to get much more HP out of catback...may be worth trying the DP and UP w/ the stocker first.

 

I am in the same position as you...clients and suits...

Having had a few exhausts(SPT V1 and Megan CBE), and personally hearing a few others(AVO, Perrin, Borla).....ALL of them were considerably louder than stock. Only one combo (my current one), and with the exception of the Borla was acceptable on terms of noise/whp like you are looking for. The Borla does keep the piping on the small side, so if your future mods put you above 310+whp, you might outgrow it.

 

My setup:

 

Cobb DP(catted)

Perrin Mid/Y-pipe

Modded Stock cans - (inlet pipe is drilled with 10 3/8" holes)

 

***NOTE***

 

My comments above are based on a full TBE. This is important, as just adding the CBE alone will not be the same as a TBE;) Even the mild Borla setup gets a little throaty.

 

Being that this is largely a subjective opinion topic....MY Megan CBE was LOUD! It was subtle at idle, but when I put my foot into the "loud" pedal, trust me, the car would roar. Had many comments on how taken aback the passenger's were. They were not expecting the vocals to be quite so in your face. Even some STI junkies. This is a highly debated subject, but I felt you should hear from the conservative side as well.

 

So it wasn't just others like me, "who prefer speaking softly, but carrying a big stick";)

thanks for the advice guys

 

edmundu u have any pics u can post of ur setup also did u replace ur uppipe

hope this isnt a threadjack but heres my question anyway...will i notice a difference in power between the spt v2 and the borla? i like them both for being quiet but sounding really nice mated to a dp, but i can find the borla for a few hundred cheaper. both will mate to the cobb dp with no problems right?

hope this isnt a threadjack but heres my question anyway...will i notice a difference in power between the spt v2 and the borla? i like them both for being quiet but sounding really nice mated to a dp, but i can find the borla for a few hundred cheaper. both will mate to the cobb dp with no problems right?

 

No, never, no matter how much you mod down the line.

i can find the borla for a few hundred cheaper.

 

how much? where at?

how much? where at?

 

found this site when i was looking at the reviews for the borla:

http://www.goborla.com/product.php?productid=337421

 

with that price, it makes it a lot more desirable over the spt for me.

My HKS silent hi power could be an option for you, the only thing i would be concerned about is the look, They are very aggressive looking which may be more conspicuos than the sound they produce which is deffenitley queit however I have a feeling that any noticible exuast tone that comes from aftermarket systems will be aggresive regardless of the noise, which is offensive however not as much as the high noise level that some of them produce. Today is my first day with it on so i want to tell you to get it. GET THE HKS SILENT HI POWER.

 

Silent powers are mean. I've got one that must be atleast 5-10 years old, and it's turned itself into a hi power now! the age of it and increase in exhaust diameter and power has caused the packing to fall out of it! (Recently done allot of power mods)

 

This is with a 3" Catless downpipe, stock 2.5 midpipe (im fixing that when i can afford to) and a 3" endpipe with the HKS on it:

[ame=http://www.youtube.com/watch?v=g0OUuI2JDJc]YouTube - 98 Legacy GTB Exhaust. Single turbo.[/ame]

that sounds real nice that is what i am lookin for decible lvl wise

Well I got that, but when dealing with flow you deal with bottlenecks, and the point at which the 3" tapers to 2.5" in terms of restriction of flow, rather than capacity/total volume, would seem inhibiting.

 

Volume will certainly apply to the creation of backpressure in a good way, and it would definitely apply in the intake for reasons of pressurization/lag in that sense. But as far as diameter/restriction of flow I would think only the smallest diameter portion would matter. In this case the part of the Y before the split -- after the split, there would certainly be no problem.

 

You do realize that the farther from the engine the exhaust gets the cooler it gets, and substantially shrinks in volume because it is a gas?